EOutOfResources in DLL - c++builder

Question

I migrated several DLLs and an application from Embarcadero C++ Builder XE to C++ Builder 10.1 Berlin.
Now when my DLL (which contains forms) gets loaded by the application, I get
EOutofResources "Das angegebene übergeordnete Element ist kein übergeordnetes Element von '%s'"
in TApplication::CreateHandle
After searching for hours, I found no one with the same error, not even the english translation. I would translate it as "The specified parent element is not a parent element of '%s'".
My stacktrace:
When I set breakpoints in my DLL's code, none are triggered, so I am not sure why there is even a call to the TApplication constructor (there IS one in my code, but it doesn't seem to be called).
I suspect some issue with dependencies, so I used dependency walker and it found two 64-bit dlls. Not sure if this is a false positive:
What can I do to fix or diagnose this further?

Answer 1

I tried starting a new VCL type project to see if there were differences in the project setup, and lo and behold:
<PropertyGroup>
<ProjectGuid>{E8815773-6421-4FB8-A109-F4F505A67A2E}</ProjectGuid>
<ProjectVersion>18.2</ProjectVersion>
<FrameworkType>VCL</FrameworkType>
<AppType>Application</AppType>
<MainSource>Project1.cpp</MainSource>
<Base>True</Base>
<Config Condition="'$(Config)'==''">Debug</Config>
<Platform Condition="'$(Platform)'==''">Win32</Platform>
<TargetedPlatforms>1</TargetedPlatforms>
</PropertyGroup>
The newly created project has an element FrameworkType set to VCL. My migrated project had this set to None. After changing this to VCL, the error went away.